I kid you not: those objectives are meaningless until you've read the books above and done more research. For example:

1) Let's assume you can get 3000 on two servers. Let's further assume that you have an independent DB backend. That's 3 servers. If renting, that's roughly 500 USD per month per computer or 1500 USD/mo. Now add bandwidth. To support 3000, I would go no less than with a 3 Mbs line, or roughly another 1500 USD/mo. That's 3000 per month just in hardware and bandwidth. Now what about customer service? You have to hire them (another 2000 USD/mo) and train them so that you have to hire a few months prior. In short, you are looking at around 10,000 USD/mo to run your game: where is this money coming from BEFORE the subscriptions? What happens if you don't hit your 3000 target? And where is any development budget?

2) The server better take care of EVERYTHING. Fundamental MMOG mantra: C/S is the only way. The Serve is god; the client it's servents. Put EVERYTHING you can on the server to make the client as "thin" as possible.

3) You better know inimitely what you "space" is and how it breaks down. Stripped of the game, an MMOG is a virtual world that a person navigates through. This means that you may have no choice but to put each solar system on a separate server... especially if you intend to have 1000's of ppl per system. What every your design, the way you break up your Virtual World among your Physical Computers is a huge decision.


Have you thought of the above?
Are your thoughts formalized into a Game Design Document?
Do you understand the networking and programming enough to create a Technical Design Document?

If not, then you are aiming too high by planning the game at this stage. It would be best to keep the concept alive ("a space game") but read through the above and do your research so that this concept is solidified in current MMOG industry reality.